Most homeowners making their first solar purchase spend significant time comparing panel brands and financing terms. They spend considerably less time thinking about who will actually put those panels on their roof. Yehuda Gittelson, a NABCEP-certified installer with Solaris Energy Solutions in Portland, has seen this pattern repeat often enough to have a clear opinion about it.
“People will spend three hours reading reviews of different panel manufacturers,” he said. “They spend maybe 20 minutes thinking about the installer. The panels matter a lot less than the installation.”
That gap between consumer attention and installation quality has real consequences. A photovoltaic system is not a consumer appliance. It is a structural and electrical modification to a building, governed by the National Electrical Code, subject to municipal permitting and inspection, and expected to perform for 25 years or more. The person who does the work determines how well it actually functions over that span — and whether the flashing holds against a Maine winter.
What the Credential Tells You
Maine does not require NABCEP certification for solar installers under state law. It does require that electrical work be performed by licensed electricians. But the broader installation work — racking, structural attachment, module placement, system commissioning — falls into a category where licensing requirements vary and enforcement is uneven.
NABCEP’s PV Installation Professional credential fills part of that gap. The certification is accredited to the ISO/IEC 17024 standard for personnel certification bodies, which means it meets an internationally recognized benchmark for assessment validity and reliability. It requires documented field experience, accredited training hours, and a passing score on a rigorous exam. In Maine and a small number of other states, NABCEP certification is tied directly to eligibility for state rebate programs — meaning that installers without the credential can legally operate, but may not qualify a client’s system for certain incentive pathways.
Beyond rebate eligibility, NABCEP maintains a publicly searchable directory of certified professionals. A homeowner in Cumberland County who wants to verify Gittelson’s credentials before signing a contract can do so in under two minutes. That accountability layer does not exist for an uncertified installer.
“The directory is public for a reason,” Gittelson said. “If I do bad work, my name is attached to a credential someone can pull. That matters. It’s not a guarantee — but it changes the calculus.”
What the Invoice Doesn’t Show
The line items on a solar quote — panel cost, inverter cost, labor, permit fees — do not capture what a crew actually does on site. They do not capture whether lag bolts are torqued correctly or whether roof penetrations are properly flashed. They do not reflect whether the installer performed a load calculation before recommending a system size, or whether the string configuration accounts for seasonal shading from a neighbor’s tree. These are the details that determine whether a system performs at its rated output or quietly underperforms for years.
Gittelson’s mechanical engineering background from the University of Maine at Orono informs how he approaches system design before a single panel leaves the truck. He factors in roof orientation, pitch, shading patterns, and the client’s monthly consumption profile. Most residential installers in Maine work from software-generated estimates, which are reliable when the underlying data are accurate and less reliable when they are not. A certified installer with field experience knows when to trust the model and when to override it.
The average Maine homeowner needs roughly an 11-kilowatt system to cover typical electricity consumption, at a pre-incentive cost of around $32,000. That is a purchase most people make once. The federal residential solar tax credit, which allowed homeowners to deduct 30% of system costs, expired at the end of 2025 under current law, making the selection of a competent installer more important, not less — there is now less financial cushion to absorb the cost of remediation if something goes wrong.
The Long Tail of Installation Quality
Operations and maintenance work has become one of the fastest-growing segments of the solar workforce nationally, expanding more than 116% over the past five years as the installed base of aging systems requires professional attention. Gittelson expects that trend to shape his own work over the next decade. Systems installed between 2015 and 2020 are now reaching the point where inverters need replacement, and in some cases, racking components require inspection.
When a technician opens up a system installed by someone else, the quality of the original work becomes immediately apparent. Properly labeled circuits, clean conduit runs, correctly torqued hardware, accurate system documentation — these are the markers of an installation done with care. Their absence is the marker of one who was not.
“I’ve pulled apart systems that were installed by people who clearly knew enough to get a permit approved,” Gittelson said. “That’s not the same as knowing enough to build something that holds up.”
Maine’s solar stock has grown from 62 megawatts in 2019 to 977 megawatts by 2024. That installed base will need maintenance, repair, and eventual component replacement for decades. The installers who carefully document their work, use correct materials, and build systems that comply with current code will generate fewer problems. The ones who cut corners will generate more — and the homeowners who hired them will bear the cost.
For Gittelson, the consumer-facing implication is straightforward: asking an installer for their NABCEP credential number and spending two minutes verifying it in the public directory is a faster and more informative check than reading 50 online reviews.